His father, Captain Robert Dillon of Loughglynn,[1] was a member of the landed gentry.

Theobald and Mary had six sons: —and two daughters: In the 1680s Dillon was lieutenant-colonel in Clanricarde's Regiment of Guards of the Irish Army.

[21] Both fought in the Williamite war in Ireland, but the second, Arthur Dillon's was sent to France with the Irish Brigade in April 1690 in exchange against the Lauzon's French Expeditionary Force.

[24] His widow was killed accidentally by the explosion of a bomb during the Siege of Limerick on 7 September 1691.

However, in 1694 his son Henry managed to obtain a reversal of the attainder and succeeded to title and lands.